Distributed feedback (“DFB”) lasers are a solid state diode laser technology that incorporates a diffraction grating into the active region of the laser. The DFB design allows for the emission of stable, single wavelengths that are slightly tunable via temperature change. The combination of multiple DFB lasers into a concatenated DFB quantum cascade laser allows for an expansion of the tunability of this technology. However, concatenated DFB QCLs suffer from high losses when unused laser sections are unbiased, and from high power usage when biasing is used. It would be advantageous if DFB-QCLs could be created that are more power efficient and yet still offer the expanded range of wavelengths observed with concatenated DFB-QCLs.